20GR105065R / PHILIPS [TV]

• Automatic fine tuning (AFT) field alignment procedure.
• Intermittent destruction of line o/p transistor. (part of circuit diagram displayed)
• No voltage from PSU. (with circuit diagram extract)
• Power supply fault finding. (extract of circuit diagram attached)
• Microcomputers and screening plate.
• Difficult to tune programmes, stations shifted on tuning bar.
• Dead. Only hum from speakers. (part of circuit diagram displayed)
• Dead. Low hum.
• Tuning drifts. only on certain channels.
• Does not shut down (when cold).
• PSU check.
• No colour.
• No regulation. (+ extract of circuit diagram)
• Low audio. (+ extract of circuit diagram)
• Volume varies. depending on picture content. (part of circuit diagram displayed)
• Stuck in standby. (with circuit diagram extract)
• Hotel Mode activates by itself. (+ extract of circuit diagram)
• New infra red receiver.
• Power supply does not oscillate. (picture attached)
• No tuning, no remote volume control. (part of circuit diagram displayed)
• Intermittent colour and intermittent dark vertical bar on picture.
• Skips channels during tuning. only on certain channels.
• No frame or short frame. (extract of circuit diagram attached)
• No picture. OSD OK .
• Search jumps on UHF.
• Picture is poor with rippling on verticals. (extract of circuit diagram attached)
• Stored channels drift off tune briefly after switch on. Crackle in sound.
• No tuning possible, F2 appears on bottom of picture and S1 on top.
• Poor sound, cannot be adjusted louder. When adjusting, sound cuts out. (+ extract of circuit diagram)
• Programming unoperational. Limited sound adjustment possible.
• Intermittent colour.
• Field collapse normally with blank picture. (part of circuit diagram displayed)
• No function. Standby LED flashes briefly. (with circuit diagram extract)
• Slow start-up.
• Excessive brightness.
• Streaks in picture. Picture pulls and rolls intermittently.
• Blank raster. Flyback lines. (extract of circuit diagram attached)
• PSU does not start up, if appliance was switched off for a day. Appliance functions after short switch on/off. (with circuit diagram extract)
• Lines on picture after approx one hour. It consists of a band of bright white lines about two inches wide. (part of circuit diagram displayed)
• Unstable tuning.
• Display goes to F1 a few seconds after switching the set on.
• No sound. No picture. Faint motorboating noise. (service info for PHILIPS -20GR105065R)
• No line start up; +95 available; +9V is about 4.5V. (+ extract of circuit diagram)
• After operating for one hour it is no longer possible to switch over programmes not even from the front panel. Appliance must be switched on and off then it is possible to change channels.
• No standby, humming and standby LED blinks.
• Tuning drifts. (with circuit diagram extract)
• Line tearing, especially with bright scences. (+ extract of circuit diagram)
• SIF DET adjustment procedure.
• No tuning. (+ extract of circuit diagram)
• Processor numbers (changed).
• No start up, just a buzzing noise in speakers. (part of circuit diagram displayed)
• Slight foldover at upper part of picture if appliance is switched on when cold. Fault disappears after few minutes. (picture attached)
• No start-up. Buzzing from speakers and working noise of PSU.
• No audio.
• Replacing the EAROM. (part of circuit diagram displayed)
• Service manual correction. (+ extract of circuit diagram)
• Does not switch on. LED is lit in standby. If appliance is switched on with RC, LED switches off.
• No functions. after start-up (intermittently).
• No picture and sound. Low hum intermittently, no function.
• Sound motorboating when cold. (part of circuit diagram displayed)
• Tripping. (with circuit diagram extract)
• Dead. Low level buzz from loudspeaker. (extract of circuit diagram attached)
• Reluctant to start from cold (picture attached)
• Buzzing sound then switches off.
• Green picture.
• Colour flickers. No colour. after a while. (+ extract of circuit diagram)
• Error messages indicated by front display flashing. (+ extract of circuit diagram)
• Colour sync adjustment procedure.
• Reduced vertical size. at top.
• Line output transistor becomes warm and in the course of time it becomes defective. (+ extract of circuit diagram)
• No functions. Sound buzzes in loudspeaker. (+ extract of circuit diagram)
• No functions. Hum in loudspeaker. No LED lit.
• Excessive green.
• No start-up. (with circuit diagram extract)
• How to reset microprocessor.
• Line output transistor fails repeatedly. (+ extract of circuit diagram)
• PSU switches off with load at U95V. (with circuit diagram extract)
• No switch on after activating mains switch. Whistling noise. (part of circuit diagram displayed)
• Vertical line. on the right half screen. (picture attached)
• Wavy picture. on the right.
• Crackling and popping in sound after a short time.
• Quick hiccup. (part of circuit diagram displayed)
• Does not start up. Light buzz from loudspeaker. Standby LED produces one brief blink.
• No audio. (20GR105065R PHILIPS repair tip)
• No freeze frame or intermittent freeze frame; no sound. (part of circuit diagram displayed) (PHILIPS - 20GR105065R information)
• No HT from chopper circuit. (with circuit diagram extract)
• Dead. (extract of circuit diagram attached)
• No OSD. Picture OK .
• Interference in audio. Interference in picture. (with circuit diagram extract)
• Line output transistor TR7528 fails at switch on.
• Volume can't be tuned down. No tuning with RC. (+ extract of circuit diagram)
• Dead when switched on via mains switch. Though appliance is on, red LED flashes. Can be switched over to standby. If left in standby for 1 hour and then switched on via RC, functions.
• Colours flickers and disappears.
• Microprocessor screening plate. (+ extract of circuit diagram) (20GR105065R PHILIPS repair tip)
• Dead set. Tries to start.
• Sound varies with picture content.
• No tuning bar when install button pressed and set not in hotel mode. (with circuit diagram extract)
• Unstable tuning.
• Picture is mostly green with flyback lines after 10 secs from switch on.
• Appliance hums slightly (no speaker) horizontal end stage and power supply transistor are ok. Unfortunately no service instructions available.
• Sound varies with picture content.
• Right hand side of screen has a line.
• Tuning menu can not be called. All other functions OK.
• Modification introduced to +9V supply.
• The remote control only controls the volume and sound-stop. No function with On-Off and channel change-over, although the display for the operation flickers.
• No function, starts up from standby, then goes out.
• Lines across top of picture about 8" in first 100 lines. (+ extract of circuit diagram)
• Won't tune a new channel. Won't activate store function. Picture OK. Sound OK.
• Green picture. after warm-up. Lines in picture. after warm-up. Does not change channels.
• Picture shifted to the right. (+ extract of circuit diagram)
• 10V on 95V line. (picture attached)
• No line output.
• Does not start. Slight buzzing in loudspeaker.
• The tone (sound) tunes well, but the volume cannot be raised. (20GR105065R tip from PHILIPS)
• During picture changes sometimes a volume increase (plop) is heard. (with circuit diagram extract) (20GR105065R tips)
• Line output stage TS7528 is defective. (extract of circuit diagram attached)
• R-Y and B-Y discriminator adjustment procedure. (extract of circuit diagram attached)
• Vertical size varies. intermittently.
• No channel search. No OSD. (extract of circuit diagram attached)
• No start up from cold and humming.
• After switching on the CTV "EXT...1.2.3..." appears on the screen.
• Picture displays lines and strange foldover effect at centre. (20GR105065R tips)
• Standby LED lights up and switches off at power on. Appliance will not start up.
• Stops working every 2 or 3 hrs. Only starts again after switching off and on again.
• Control panel cover.
• Line chirps intermittently. Appliance does not start. Only hum from loudspeakers.
• Dead. At switch on the stand by LED flashes.
• Initial volume level is higher than maximum Hotel mode setting. (20GR105065R PHILIPS repair tip)
• Line out of phase. Black band in centre of screen. No colour.
• Intermittent colour. (PHILIPS - 20GR105065R information)
• How to de-activate Hotel-Mode.
• Trips. (+ extract of circuit diagram)
• Switches off by itself. after a while. (picture attached)
• No function at switch on from standby. Switches to LOCK (hotel) mode. (picture attached)
• No picture. No sound. Purring sound in loudspeaker. (+ extract of circuit diagram)
• No start-up. when cold. (part of circuit diagram displayed)
• Colour amplitude and phase adjustment procedure.
• Bright flash on screen. No picture or sound. (part of circuit diagram displayed) (PHILIPS - 20GR105065R information)
• "Store" key does not work. (+ extract of circuit diagram)
• Intermittent green picture, channels cannot be programmed. (picture attached)
• No function. Motorboating from PSU. TV starts up randomly. Intermittent fault.
• Memory cannot be opened via "rhombus". Stored channels cannot be changed.
• Right side of picture discoloured.
• Description of SMPS. (picture attached)
• Production change to line drive. (+ extract of circuit diagram)
• No colour. (part of circuit diagram displayed)
• Vertical collapse. (part of circuit diagram displayed) (20GR105065R tips)
• Change of C2523.
• No colour. (service info for PHILIPS -20GR105065R)
• White balance adjustment.
• Reluctant to start up from cold.
• Delay RF AGC adjustment procedure.
• Focus adjustment. (20GR105065R tips)
• High voltage transistor defective after a while.
• No output from the chopper power supply which uses a junction FET, whose gate and source are at 12V while 300V is present at the drain. (picture attached)
• Intermittently narrow picture, but corrects itself shortly after.
• Doesn't store stations correctly.
• Green picture. (part of circuit diagram displayed)
• SOPS defective. (with circuit diagram extract)
• To put into hotel mode.
• No start-up. Standby LED flashes .
• Dim picture with Hanover bars visible. (extract of circuit diagram attached) (20GR105065R tip from PHILIPS)
• No +9V, line output stage is OK. (with circuit diagram extract)
• Becomes defective immediately after switch on.
• Picture separating line appears. Whistling.
• Green picture.
• Line output stage does not function.
• Distorted audio.
• Whistling from PSU. (extract of circuit diagram attached)
• No tuning. No channel lock. (extract of circuit diagram attached)
• U743 tuner replacement. (with circuit diagram extract)
• Loosing colour during play-back of a video tape. (with circuit diagram extract)
• Intermittently dead. after start-up.
• No audio.
• Only half a picture. (with circuit diagram extract)
• No start up. No standby. Attempts to start up, but fails.
• New IR receiver.
• Very slight vertical foldover with interferences similar to EHT arcing, especially on very white scenes. (PHILIPS - 20GR105065R information)
• Sometimes when turned on, green screen only with flyback lines, at other times no tuning and channel will not change. (extract of circuit diagram attached)
• Protection device (thyristor THY6641) is triggered at switch on. (extract of circuit diagram attached)
• Whistle.
• Initial volume level is higher than maximum Hotel mode setting.
• Slow start up of power supply. (picture attached)
• Programme tuning difficulty, stations shifted on tuning bar. (extract of circuit diagram attached) (20GR105065R tips)
• Vertical roll. (extract of circuit diagram attached)
• Appliance is dead with standby LED flashing after a few seconds. (part of circuit diagram displayed)
• Low 5V to micro chip. (+ extract of circuit diagram)
• Sound increases intermittently or "pops", especially during bright scenes. (extract of circuit diagram attached)
• No connection for headphone.
• No functions. Standby LED flashes. Relay switches to ON.
• Fizzling sound from speakers at start-up and intermittently picture jagged. (PHILIPS - 20GR105065R information)
• No colour in OSD.
• Hums softly. (picture attached)
• Using a lamp as a load.
• Replacement of TDA7052 with a TDA7052A.
• LED does not flash. Slight buzz in appliance. (with circuit diagram extract) (20GR105065R PHILIPS repair tip)
• Print with linearity coil pos. 5800.
• Vertical oscillator adjustment procedure.
• Comes on in standby. When program button pressed standby lamp blinks then goes off.
• Store lock on the appliance. (20GR105065R PHILIPS repair tip)
• Drive for high voltage missing. (extract of circuit diagram attached)
• PSU peeps +95 is ca 0,8v
• No function. When switching on with RC, standby LED lights up. (extract of circuit diagram attached)
• Local controls inoperative. (PHILIPS - 20GR105065R information)
• Stored channels are partially lost.
• Dead. Only standby-LED works. Responds to TURN ON command, but no image and no sound.
• Sound returns gradually after channel change. (with circuit diagram extract)
• Chopper inoperative. (extract of circuit diagram attached)
• Search jumps on UHF.
• The removal of leaded diodes. (picture attached)
• Does not start up at once from cold.
• Stations won't change. Picture and sound OK. Other functions OK.
• V-centre adjustment procedure.
• Difficultly in tuning to correct position.
• Dead due to action of over voltage protection circuit. (20GR105065R PHILIPS repair tip)
• The following production changes were introduced to prevent the set coming on in the store lock mode when switched on from standby. (part of circuit diagram displayed)
• Stuck in hotel mode.
• Modification at line transformer position 5530. (picture attached)
• Cannot be programmed and search does not function. Only limited volume adjustable.
• No picture. Audio OK .
• Trips. at start-up (intermittently). (extract of circuit diagram attached)
• No start-up. intermittently.
• Set won't tune to high frequency channels and lower frequency channels appear to be higher. (with circuit diagram extract)
• How to switch off Hotel-Mode.
• Control micro processors.
• Random breakdown of line output transistor. (with circuit diagram extract)
• Dead with whistling noise coming from power supply. (with circuit diagram extract)
• Poor sync. AGC fault.
• Spurious nonsense OSG. Goes to standby after 0.5-2hrs. Loss of tuning.
• 6613 type change. (picture attached)
• Buzz in audio. No picture.
• No functions. when cold.
• Doesn't tune stations correctly. When cold, crossed lines on low UHF channels. (extract of circuit diagram attached)
• No operation.
• No audio.
• Appliance will not switch on at times, but hums in the power supply section.
• No HV. (20GR105065R tip from PHILIPS)
• Settings do not stay in position.
• Vertical vibration in cold condition of set.
• Volume goes to max. No volume control.
• How to de-activate volume limiter.
• Tuning procedure.
• Initial volume level is higher than maximum hotel mode setting.
• Line tearing. on lower half screen. (+ extract of circuit diagram)
• +9V supply modification. (+ extract of circuit diagram)
• Blue picture. Coloured lines.
• No voltage from PSU, computer does not work. (picture attached)
• Tuning drifts. only on certain channels (after a while).
• Low audio.
• No sound. Picture OK. After a short time TV stops. High frequency noise from PSU. (with circuit diagram extract)
• Blank raster. No audio. after a while. (picture attached)
• Excessive horizontal size.
• Green raster. Faint picture. Flyback lines. (20GR105065R tips)
• No power with abnormal sound. (picture attached)
• Unstable tuning.
• Height excessive. Defective linearity. Field blanking. (extract of circuit diagram attached) (20GR105065R PHILIPS repair tip)
• Noise in sound. Mute does not function.
• Set goes accidentally into hotel mode.
• Standby just pulsing.
• Will not tune, drifts, colour disappears or interference on a certain channel. (e.g. channel 5 and 59)
• Limited volume. No channel search.
• Picture shifted horizontally. (part of circuit diagram displayed)
• Memory loss. (+ extract of circuit diagram) (20GR105065R PHILIPS repair tip)
• Stops at start up. (extract of circuit diagram attached)
• Picture appears slowly.
• Appliance can not be programmed. Search does not function. Only limited volume control.
• LED flashes once, then gurgles. (with circuit diagram extract)
• Picture passes out in the centre.
• No horizontal synchronisation. (extract of circuit diagram attached)
• To improve performance with prerecorded cassettes. (extract of circuit diagram attached)
• Adjustment of +95V. (extract of circuit diagram attached)
• After working normally for a while the TV blocks in any position. The functions do not work.
• No picture. TXT OK . (extract of circuit diagram attached)
• Search jumps on UHF.
• Enable Hotel mode.
• Colour disappears with VCR-scan (picture search). (part of circuit diagram displayed)
• Programme channel search cannot be called up.
• Smeary, washed out picture with bent verticals. (extract of circuit diagram attached)
• Intermittent colour.
• No audio.
• Buzz in audio (intermittently). (with circuit diagram extract)
• Line transistor 7528 blows within 1 sec. (picture attached)
• Dark picture.
• Colours flicker and disappears.
• Only some programs with snowy picture can be tuned and on band 1 missing some programs. (picture attached)
• No picture. No sound. Switching on and off from Standby OK.
• No transmitters to adjust and the sound is not controllable.
• Line output stage only starts up for a short time. (extract of circuit diagram attached)
• Vertical amplitude cannot be fully adjusted, TXT lines can be seen. (picture attached)
• How to switch OFF Hotel-Mode.
• Difficult startup. Rattling sound from line output trafo. (20GR105065R PHILIPS repair tip)
• When switching on, only a 10cm stripe on top of screen, the rest of screen is black with flyback lines. After a while, stripe becomes wider. (part of circuit diagram displayed)
• Searches for channels continuously. (picture attached)
• To remove store/lock.
• Switches to standby. (part of circuit diagram displayed)
• Sound goes to max. intermittently and HT varies. (with circuit diagram extract)
• Appliance does not function with standby light flashing.
• Green picture with retrace lines. After a few restarts picture OK.
• Programs and PP-settings cannot be changed.
• Dim picture with Hanover bars.
• No colour.
• Identification coil adjustment.
• Bright flash on screen and no picture or sound after a few minutes. (+ extract of circuit diagram) (20GR105065R tip from PHILIPS)
• The TV cannot hold the picture.
• The switched-mode power supply cannot be loaded.
• Colours flickers and disappears.
• Picture fails for a short time. (picture attached) (service info for PHILIPS -20GR105065R)
• Line down middle of screen. (+ extract of circuit diagram)
• Set dead with just 5V on the 95V line. Standby LED is on but set won't start. (part of circuit diagram displayed)
• No picture or sound but RCU works correctly. LED flashes when the handset is tried. (extract of circuit diagram attached)
• Failures in the power supply. (+ extract of circuit diagram)
• Unregulated power supply. Pulsating picture and surging sound. (extract of circuit diagram attached)
• Field foldover at switch on from cold. Effect disappears when appliance warms up. (picture attached)
• Blank or green raster. Flyback lines. Faint picture or normal picture. (extract of circuit diagram attached)
• Loud chriping after switch on. It becomes lower after a short time.
• Dead. Strange noises from PSU/ line output transformer. (picture attached)
• Blank raster. OSD OK .
• Memory content dropout at positions 4 and 5.
• Strongly distorted sound by low volume.
• Sound varies with picture content.
• The TV does not stop during the tuning phase. (20GR105065R tips)
• No tuning. only on certain channels.
• Intermittently no picture and sound at switch on. Buzz from speaker. (picture attached)
• Enter service mode.
• +B very high. (extract of circuit diagram attached)
• How to enter/exit HOTEL mode. (PHILIPS - 20GR105065R information)
• Line output stage does not start up. (part of circuit diagram displayed) (20GR105065R tips)
• Line tearing and rope effect.
• Unable to retune set or set analogue levels. Store-lock option may be on "Hotel mode".
• No picture. No audio. (picture attached) (20GR105065R PHILIPS repair tip)
• Picture shifted to the left. intermittently. Line tearing. intermittently. (with circuit diagram extract)
• Poor synchronisation. (with circuit diagram extract)
• Volume change with great fluctuations in brightness. (part of circuit diagram displayed)
• No line output stage. (with circuit diagram extract)
• Skips channels during tuning. (part of circuit diagram displayed)
• Comes on for a short time.
• Picture shifts. (picture attached)
• No audio.
• Excessive HV. after a while.
• Picture centering has shifted horizontally. No OSD.
• PAL colour amplitude adjustment procedure. (20GR105065R PHILIPS repair tip)
• No tuning.
• Dark picture. Audio OK .
• Enable Hotel mode. Disable hotel mode.
• Unstable tuning.
• Secondary main power supply OK except +9V at 5.8V
• To release hotel mode (child lock).
• No functions. Slow start-up. (+ extract of circuit diagram)
• Change of C2523.
• Green screen and at other times no tuning. (part of circuit diagram displayed)
• No tuning. Impossible to change analog control adjustments (brightness, sound, etc.). (picture attached)
• Slow hiccup (picture attached) (20GR105065R tip from PHILIPS)
• White unmodulated raster. Picture missing. (with circuit diagram extract)
• Green screen with flyback lines. Green oscillations. Noise as if HV leaky on picture tube base. (picture attached)
• No start-up. intermittently (when cold). (with circuit diagram extract)
• Set does not retune or program etc
• How to de-activate Hotel-Mode:
• No or intermittent start-up. (with circuit diagram extract)
• Error codes.
• Dead. Power LED is OFF (ON in standby). Hissing from PSU.
• Change of C2523.
• Two lines going around. (part of circuit diagram displayed) (20GR105065R PHILIPS repair tip)
• Initial volume level is higher than maximum Hotel mode setting.
• Blown chopper. (with circuit diagram extract)
• Bell filter adjustment procedure.
• Cannot change tuning or stored settings. (+ extract of circuit diagram)
• No picture (when cold).
• Horizontal oscillator adjustment procedure.
• Buzzing from PSU. when cold. (+ extract of circuit diagram)
• Whistling.
• Unable to tune or set volume in Prefix mode.
• Sound varies with picture content.
• No function. Standby-LED lights up. Appliance switches on but no picture or sound.
• Horizontal white line.
• Dead. Low frequency noise on sound.
• No picture, sound ok but on turning up A1 control, frame collapse. (with circuit diagram extract)
• Excessive vertical size. (20GR105065R tips)
• Tuning drift, when it is hot the tuning is lost on channel change.
• No power supply start up in loaded condition (eg. with lamp).
• Does not switch on, standby LED OK.
• Replacement of surface mounted diode 6637. (with circuit diagram extract)
• The fuse and the bridge diodes in the power supply blow.
• Menu rolling. (picture attached)
• Picture only in two bars in upper screen section, the rest is dark. (part of circuit diagram displayed)
• CRT types.
• How to de-activate Hotel mode.
• Poor synchronisation. when cold. (picture attached)
• Occasionally appliance does not switch on from standby. No further functions are possible.
• No SOP supply. (+ extract of circuit diagram)
• Hazy flickering picture at top. (+ extract of circuit diagram)
• Low frequency noise on sound.
• Green picture after few hours, intermittently fault disappears for short while when switching from a station to another. Strange characters in OSD.
• No switch on. Low noise on sound. (part of circuit diagram displayed)
• Horizontal hold adjustment procedure.
• 95V available. 9V is only 5.2V. Slight buzzing from loudspeakers.
• Set comes on in store lock mode. (extract of circuit diagram attached) (service info for PHILIPS -20GR105065R)
• Does not stop on stations.
• No tuning or on screen tuning display.
• How to switch off Hotel-Mode:
• No tuning - no channels.
• Bright picture. Flyback lines.
• Noise in audio.
• Picture is faint with hanover bars. (with circuit diagram extract)
• Defective purity. (20GR105065R PHILIPS repair tip)
• Red picture. Flyback lines.
• Reduced horizontal size. (+ extract of circuit diagram)
• After replacement of the line output transistor BUT12, picture with trapezoid effect, BUT12 overheats and goes defective again. (extract of circuit diagram attached)
• No sound or raster. The 95V HT supply is present at the line output stage but there is no line drive. (+ extract of circuit diagram)
• Turns on automatically. No RC or front panel controls.
• Initial volume level is higher than maximum Hotel mode setting.
• Squealing from PSU.
• Hotel mode.
• Line output transistor running hot. (with circuit diagram extract)
• Line output transistor replacement.
• Humming, motor noise and other unusual noises. Normal picture. (20GR105065R tips)
• Connection of a loop system to the TV.
• Dead, very slight whistle from PSU. (service info for PHILIPS -20GR105065R)
• Change of C2523.
• Correction to service manual LOT winding.
• Defective IC7103 SV-production. (with circuit diagram extract)
• Intermittently dead. (+ extract of circuit diagram)
• White screen with flyback lines. Excessive brightness which increases until PSU switches to protection mode. (+ extract of circuit diagram)
• Green screen with flyback line. No picture. OSD OK.
• LED switches on then off immediately.
• Change of C2523.
• Buzzing.
• No colour and vertical black bar across screen.
• No audio.
• Programme tuning difficulty. Stations has shifted on tuning bar. (20GR105065R PHILIPS repair tip)
• No functions, hum in loudspeakers. (picture attached)
• Intermittent audio and picture. (extract of circuit diagram attached)
• Intermittent channel drift in UHF. Channel search OK. VHF OK.
• Poor reproduction of copy protected tapes. (picture attached)
• No switch on. Weak whistling noise from PSU. LED is OFF.
• No sound or picture. Low hum from speaker. (part of circuit diagram displayed)
• No picture. (extract of circuit diagram attached)
• No vertical deflection. (part of circuit diagram displayed)
• Rolling or jittering picture. (picture attached) (PHILIPS - 20GR105065R information)
• Does not regulate +95V. (20GR105065R tip from PHILIPS)
• Frame has shifted sideways. Appliance whistles and does not oscillate correctly. (with circuit diagram extract)